Help Please.

[mcstang]

Greetings from Scotland,
I need some serious help and I hope you folks can help out.
I own a 2005 GT Auto with 55k on the clock.
I bought it in Aug 2010 with 30k and it was awesome. Other than a C&L street CAI and SLP's, she was stock.
She did have an engine check light on which the seller advised me was due to the car running lean due to the C&L.
She was fab. The roar was addictive and the performance outstanding-I'm sure you all know what I mean.
In April 2011 she needed a new battery.From that moment on she has been problematic. Instead of induction roar and speed I ended up with a car that sounded like a hoover with lethargic performance.
She just sounded blowie(?) and bogged down!!
She still started, stopped and generally was ok but nowhere near as good.
After some online research I bought a Diablo Predator with the intention of tuning in the C&L. I used one of the canned tunes and things improved a little but nowhere near as good as before.
Trying to get that magic back I've tried cleaning the mass air sensor, swapped the C&L for the stock box,cleaned and ultimately replaced the throttle body. All to no avail and as time has went by the car has got steadily worse.
Note that after putting in a canned tune (85mm Universal CAI) I have had no engine light.
Further online advise resulted in me getting in touch with Doug at C&l Performance. I got the three tunes; race,perf and torque.
The car seemed a little better; the induction roar was back but I felt the car was holding gear longer than it should and whilst coasting the car would change down on its own. After a couple of days the car would return to poor sound and performance-it's like the car was rejecting the tune after installation. At this stage (after car "rejected" tune), the car didn't want to go above 2000 revs.
I did note that whilst loading the tune, the dash goes through all the warnings until ultimately at 100% loaded, the display says "failsafe mode" and "engine temp warning". Is this normal? When properly loaded, there is no warnings on the display.
In the past week I've replaced the battery, reloaded the tunes several times,cleaned the MAF and still she is lousy.
Today, after a long run she didn't want to go above 2000 revs(unless I used kickdown), wouldn't change down after pushing the pedal going up hills and just feels very heavy!!
Again no engine check light!!
In summary;
She starts ok
Idle is fine
Stock box makes no difference
Maf has been cleaned several times
Throttle body is fine
Emmisions are fine.
There are no exhaust or vaccum leaks.
No undue smoke.
MPG is fine. 30 today on a good run
Kickdown is fine though I'm sure she backfires
I've also noticed from a standing start with a gradual acceleration (not flooring it), she's in 3rd gear before I hit 30mph. is this normal?

In the next week I'm thinking of replacing the MAF, changing the plugs and after that I'm clueless. Throttle body sensor?
Over here in Scotland there are no garages with our car on there diagnostic list so it can't be plugged in anywhere!
Plus remember, there is no engine check light.
So, what do you think is the issue?
This is really grating on me and if I don't find a solution she's going for a bargain on ebay.
Thanks for reading

 

[Flapjack]

Sounds like it might be plugs to me.... but you're not having any misfire codes or anything? Have you checked the plugs to see what their condition is?

Very weird that it started with the battery change. How old was the battery? Did you have the alternator tested when you changed the battery? Any alternator related engine codes (ie: P0340 Camshaft position sensor)?

Sent from my Galaxy Nexus using Tapatalk 2

 

[mcstang]

Sounds like it might be plugs to me.... but you're not having any misfire codes or anything? Have you checked the plugs to see what their condition is?

Very weird that it started with the battery change. How old was the battery? Did you have the alternator tested when you changed the battery? Any alternator related engine codes (ie: P0340 Camshaft position sensor)?

Sent from my Galaxy Nexus using Tapatalk 2

Hey Jack,
Thanks for the quick reply.
I have no idea how old the battery was, probably original as I got all the receipts with the car and none for a battery.
I only tried a new battery last week in case the one I bought nearly 2yrs ago was a dud.
I have no other alternator issues and like I say; no engine check lights or clues on the dash.
I'm kinda hoping it is the plugs-not too expensive. She does backfire under heavy acceleration. MPG is fine though??
Keep those ideas coming folks

John

 

[slowlyrolling]

When I first installed my jlt and bbr (shit) tune they tuned it for a smaller intake and it ran like you're describing. Three tunes later they got it right (as right as it could be from them.)

I'd change the fuel filter too. Couldn't hurt.

 

[mcstang]

When I first installed my jlt and bbr (shit) tune they tuned it for a smaller intake and it ran like you're describing. Three tunes later they got it right (as right as it could be from them.)

I'd change the fuel filter too. Couldn't hurt.

Thanks mate,
Thing is mine was shit prior to getting the tune so I'm thinking the tune is probably ok and it's some other underlying issue+ aint Doug the Top Man?
Car has been regularly serviced and had three fuel filters over the period.
Forgot to mention that the C&L has also been cleaned.

Keep them coming.

John

 

[BruceH]

Plug your predator in and check for dtc codes. You can also clear them with it. I haven't been in Europe for over 20 years. The last time I was there all the gasoline was leaded. I'd think it would all be unleaded by now but I'm going to ask. Are you running unleaded gasoline? Have you ever put any kind of octane booster or fuel treatment in the tank? All of those can ruin the sensors and be hard on the cats.

 

[mcstang]

Plug your predator in and check for dtc codes. You can also clear them with it. I haven't been in Europe for over 20 years. The last time I was there all the gasoline was leaded. I'd think it would all be unleaded by now but I'm going to ask. Are you running unleaded gasoline? Have you ever put any kind of octane booster or fuel treatment in the tank? All of those can ruin the sensors and be hard on the cats.

Cheers Bruce,
Yep; we have unleaded over here. We have KFC too
The predator has no trouble codes and there is no clues on the dash.
I did put in some fuel additive some months back but it made no difference-shit before, shit after.
Cats i think are fine. A mechanic checked her last week and there is nothing obvious he could see. He did test drive it and said she was under powered and had very little torque at low revs.
Basically she drives like a 1.2 litre.
He was going to look at the plugs but they looked stuck solid and didnt want to attempt removal as he didnt have replacement plugs.

Cheers so far

John

 

[BruceH]

It's probably time to order plugs and the plug removal tool in case they break. There is a whole procedure for getting the older style plugs out. 2005 are the worst because they weren't nickle plated. It involves kroil or a similar penetrating oil, patience, and alot of anxiety.

 

[mcstang]

It's probably time to order plugs and the plug removal tool in case they break. There is a whole procedure for getting the older style plugs out. 2005 are the worst because they weren't nickle plated. It involves kroil or a similar penetrating oil, patience, and alot of anxiety.

Cheers Bruce,
I hope to get the plugs seen to very soon.
She's 8 year old so probably about time.

Anyone else think plugs?

 

[05moneypit]

55K miles or kilometers? Either is kind of low for needing the plugs replaced but it is 8 years old and plugs are a good place to start....just odd that it does not throw a misfire code if the plugs are going.

When you say backfire under heavy throttle....backfire out the exhaust or in the intake?

Lee

 

[BruceH]

Cheers Bruce,
I hope to get the plugs seen to very soon.
She's 8 year old so probably about time.

Anyone else think plugs?

Like Lee mentioned it's just a place to start and it needs to be done anyway. I've never gotten 100k miles out of platnium plugs with any vehicle. 60k is the most I've gone and they looked like crap when pulled. I'd also look at the cats. You said the fuel filter has already been changed.

 

[05moneypit]

Like Lee mentioned it's just a place to start and it needs to be done anyway. I've never gotten 100k miles out of platnium plugs with any vehicle. 60k is the most I've gone and they looked like crap when pulled. I'd also look at the cats. You said the fuel filter has already been changed.

I was kind of thinking cats also Bruce but he said his mechanic "checked them". He also mentioned that it didn't sound the same.....cats or a cat plugged....again it should throw a code from the cat check O2 sensor but.....stranger things have happened. If plugs don't fix it then I would for sure look deeper at the cats.

Any other engine it would be as simple as just throwing in a set of plugs and seeing what the result is.....unfortunately we have first generation 3V's.....

Lee

 

[tungstenpony]

Just curious did you ever put all the stock parts back on...(air intake) and revert back to the factory tune to see if it ran better? I know you said you put the stock air box on but if u left the newer tune on it could still run like trash.

 

[mcstang]

55K miles or kilometers? Either is kind of low for needing the plugs replaced but it is 8 years old and plugs are a good place to start....just odd that it does not throw a misfire code if the plugs are going.

When you say backfire under heavy throttle....backfire out the exhaust or in the intake?

Lee

Hi Lee,
It's 55,000miles. I'm fairly sure it's the exhaust.
It's not serious back firing, like a gun going off...just an audible pop pop pop

Cheers

 

[mcstang]

Just curious did you ever put all the stock parts back on...(air intake) and revert back to the factory tune to see if it ran better? I know you said you put the stock air box on but if u left the newer tune on it could still run like trash.

Hi Fellow Newbie,
Yep, tried that as well. As soon as the car sounded odd (April 2011) I bought the predator and stored the original back up.Whenever I put back the stock box I put original back up back in.
Am I right in saying that because the car was already playing up, the original back up would be how the car was running at that particular time which was lousy?
On my fairly long run yesterday I noticed that the steering was awfully heavy and she seemed to be pulling with every crease in the road.
Does it figure that spark plugs=running crap=low power=alternator=power steering=this sucks?

Still No Engine Light

Really grateful for all your input to date

John

 

[psfracer]

1) Change the plugs. If you don't want to do that, at least pull each one out to look at them to see any evidence of misfire. If (for example) 6 plugs look fine and two are black, you have a misfire problem (even if you have no codes). Also keep in mind that fouled plugs don't look that obvious. If it was me I would just change them anyway.

2). When you pull the plugs, keep track of what cylinder they came from. If any are obviously fouled, check both the red and green wire from that cylinders COP to make sure its not compromised. I had that problem once as well, where one of the wires insulation was damaged and it was grounding out intermittently on the valve cover.

3) Also when you pull the plugs, check for any signs of water around the COP. If you wash your engine, you can get water in there which will cause the car to run like shit.

4) If all of this checks out--at night start your car, turn on the headlights against the garage. Turn on your radio, A/C. Roll your windows up/down and look at your headlights, if they dim significantly, replace the alternator. Normally you would have a P0340 code, but not always.

I am going with plugs first, then alternator. It doesn't matter if you are not getting an engine light or any codes. Pull the plugs. I don't think its tune related, as you stated it ran great in the beginning with the same tune.

 

[mcstang]

Cheers Dude,
Guess what?
Well tonight a cousin of a friend of a friend came round with some bleedin computer effort costing thousands and it checked just about ever possible shit.
Has the programme for tonnes of yank cars including the Mustang.
Checked everything, I mean everything. Maf, throttle sensors, 02 sensors,plugs and tonnes of other shit.
She's as clean as a whistle!!
He took her for a spin and came back with the biggest smile I've ever seen.
Said he's never driven such awesome shit and loved it.
WTF!!

After a good chat he reckoned she probably needs a friggin fuel filter!!!
I've always been bad for running the tank down to near empty and driving to work which is like one mile!!
I think I'll change the plugs as well though.

My endless search may be over.
Thanks all very much for your input guys.

Oh happy days

 

[psfracer]

Yeah I would change the plugs anyway, or at least take them out to verify.

If for no other reason--don't leave them in there for 100K miles, then when you try to remove them they are seized and you end up breaking plugs in the head. These are two piece plugs.

 

[mcstang]

Yeah, thanks again.
I'll also do that alternator test.
Honestly, there can't be many folks with a diagnostic machine which has my car in Scotland, never mind someone three streets away.
What a stroke of luck.
Well pleased.

 

[mcstang]

Sorry I'm back to pester you.....

Still awaiting a new fuel filter and plugs to be fitted.
Suspect,however,these are not going to make an once of difference.
A fuel filter was replaced about 5000 miles ago and my guy plugged in his diagnostic computer thingie again last night and went through everything again.
I have no codes and he found nothing. All sensors, cam, throttle, 02, maf....all perfect. Fuel delivery all as it should be. There has been no backfires logged and there are no issuers with the charging system.
I'm moving onto the auto transmission now. I detect a very slight slip from second to third and I changed at low speed yesterday into 2nd gear and a "engine temperature warning" and a wee red thermostat came up on the dash.
I was doing no more than 15 mph.
Any ideas what would cause this?
I have removed the C&L performance tune as the car is undriveable-she either wont change up or changes down when i'm least expecting it.
Car has been crap for a couple of years now.
I've never checked or changed the transmission fluid during this time. Car is at about 55k.
Could this be my issue?
Thanks in advance.

John